Cable telegraphy



H..ANGEL CABLE TELEGRAPHY.

APPLICAION FILED JUNE 7, 1919.

Paented Oct ll, i922.

2 SHEETSSHEET l.

QN MN mi EN www H. ANGEL CABLE TELEGBAPHY.

APPLICATION MEO Juni 1. i919.

2 SHEETS-SHEEI 2.

@Imi/614m d Patented @et lll, T922.

NETE@ STATE@ retenir HERBERT ANGEL, 0F BROOKLYN, NEW YORK,A ASSG-NOR TOTHE UNION TELEGRAPH COMPANY, 0F NEW YORK, N. Y., A COBEORATION 0F NEWYORK.

CABLE mantenerse".

. Application led June 7, 1919.

To all/whom it may concern.'

Be it known that I, HERBERT ANGEL, a subject of the United Kingdom" ot'Great Britain and ireland, residing at Brooklyn, in the county of Kingsand State of New York, have invented certa-in new and usefullmprovemeiits in Cable Telegraphy, of which the following is aspecification.

This invention relates to a method of and apparatus for operating-cableor ocean telegrapliy wherein the code' signals' are sent into `the cableautomatically by a tape transmitter and at the receiving end areselectively transmitted to the actuating magnets of a printinvrtelegraph apparatus.

Ocean cabkle operation, as at present practiced, re uires the receivedmessages to be translate `by an operator, and may, therefore, beconsidered as semi-automatic, whereas on land lines boththe`transmission. and receiving of messages is entirely automatic', themessages being translatedpanel recorded by means of an electricallyoperated telegraphic printer, the more important lines being operatedonthe multiplex system employing. a sending and receiving distributoroperating synchronously at each end of the line.

One of the purposes of my invention is to provide a method of oceancable operation employing thev` .fundamental principles or" themultiplex system on land lines; whereby the code characters may beautomatically transmitted and received rapidly and accu-y rately. Afurther object is to provide an automatic system of ocean telegraphyespecially adapted for the employment of threeunit code characters,which is the minimum number of impulses that can be used for eachcharacter.

It is well known that reversed current impulses sentf rapidly through along submarine cable are the most clearly defined at the distant en'd ofthe cable since each tollowing current has the 'effect of neutralizingthe preceding one. This principle 1nay.be utilized when a tive-unit codeis employed if succeeding impulses of like sign are suppressed in 'thetransmission and are then r introduced at theI receiving end. On theother hand, while in the three-unit code certain of the charactersrequire succeeding current impulses of like sign or polarity, yet thetime required to transmit a char- Selial lilo. 302,429.

acter of three impulses is only three-fifths of that required for afive-unit character and consequently the time period for each impulsemay be lengthened somewhat and still permit a more rapid transmission ofthe code characters.v ln this manner the wave distortion due to thecumulative eect of succeeding impulses of like sign. may be minimized,especially if the cable is grounded for an. instant between succeedingimpulses. tween successive impulses o1 i rendered unnecessary when themethod of cable operation disclosed in U. S. apnlicanon of Josepaw.minor, sei-isi ne'. @54,401 is employed. i l

l have found that the distortion of the -wave form of the impulsetransmitted lays which transmit the current impulses to the recordingdevice or printer, sh all be connected only during the intermediateportion ot' each current impulse. This results in a clear definition ofthe positive and negative character impulses. l also provid(` lier thegroundingv ot' the cable 'for an instant bctween successive impulses tominimize or nullify the cumulative effect oij successive impulses oflike sign, ln order that this invention may be clearly understood andproperly carried into effect it will now be described with reference tothe accompanying drawings. in which- Figure l is a diagram illustratingone form of apparatus which may be employed; l? i2 is chart showing theposi H negative and zero impulses correspondutto each vletter andcharacter of tl three-unit code; and Fig, 3 is a plan. view a s it' t"in perforated to indicate the charac. code.

ln the diagram the ground connections at either end of the cable and thearrangement The necessitycfor grounding belre sign is rs theA beinstalled ateachf end of the cable for duplex or multiplex operation.

The method of sending a signal or combination of signals is similar tothat in theI multiplex system. A transmitting tape 1s' to indicate thecharacters Qt lirst perforated means of a keyboardV perfothe message byrator adapted or the three-'unit code.

4perforated tape is then fed through the tionaryfcontacts-c,

of the selecting pins of the transmitter (not transmitter, advancing thespace of one character for each revolution of the sending distributer.

The automatic transmitter, indicated diaV grammatically at T, is of thewell-known type,'such as described in U. 1,298,440 'rantedf to Gr. R.Benjamin March 25, 1919. t:ln the transmitter as modified for use in thethree-unit code system, the stationary contacts are arranged in twogroups a, b of three connected against the back stops 14. When a tape isfedthrough the transmitter, one, two or .three of the movable' contactswill be moved into contact with the corresponding stab, depending uponwhich in alignment with perforations shown) are as is understood bythose famillar in the tape,

with transmitters of this type. It, however,

a blank space isfed through the transmitter, no contacts will be made.The movable contacts are electrically connected in pairs, the minus andplus contacts of each of the three positions being thus connected. Thecombinations of minus, plus and zero im ulses of the code characters areso arrange that only one movable` contact of each pair can "be moved forany code character, i. e. if the negative contact of one of the threepositions is moved, the corresponding positive contact will not be movedbecause the tape Willnever be punched on the positive and negativesidesl with perforations corresponding to the same position. Each pairof movable contacts is connected with one of the contacts 15, 15" and15c of the distributer D. After the current impulses corresponding tocode character perforations on the tape have been transmitted insequence to the transmitting relays by the rotation of the brushes onthe distributer, a current is transmitted through the contact 18 on thedistributer to actuate the transmitter magnet 17, which operates toretract the movable contacts 12, 12

The

plain S. Patent No.v

contacts, each connected respectively to the negative and posi.-V

against their backstops 14, and simultaneously move the tape forward tobring the next set of perforations opposite the selecting`pins of thetransmitter.

he .rotary distributer D which connects the contacts of the transmitterT with transmitting relaysTR, TR', operates synchronously with thecorresponding distributer D at the receiving station, the segmented andcontact rings being shown for convenience in the developed form. Theplain or continuous rings R1, R2, R3 are connected by the rotatingbrushes BRI, BR2, 'BRS with the segmented rings S1 S2 andS,.respectively. The rings S, and S3 are shown as having fifteensegments each, while. the rin S1 is provided with thirty segments.

The rushes may be' assumed to be in horizontal alignment and to movesimultane ously. As the` brush BR2 engages .the first segment of ringS2vit connects the minus and plus contacts 1 'jhrough the contact block 15awith' ring R2 which isin circuit with the coils 20,v 20 of thetransmitter relays, the return conductor 25 being connected to theintermediate or neutral point in the potentiomete coil 26, across thebus bars 8, 9. Consequently, if at this instant the minus 1 Contact. ofthe transmitter is in contact with the minus bar (L a minusor negativecurrent will flow through the relay coils 20, 20, causing the armaturetongue of relay TR to A swing overvagainst the righthand contact'- whilethe tongue of the relay TR remains against the left hand contact sinceits coil is connected reversely. This movement of the tongue of relay TRcauses a negative current to be sent into the cable from the cablebattery 30. In order that the impulse may be prolonged after the brushBR2 leaves the two segments-connected by the contact 15, the brushBRrloses a circuit through the battery 30 and the locking coils 31, 31',of the relays, thereby causing the ton e of TR toremain against theright han contacit While the brush BR1 is passing over the segmentsofring S1 which are connected by contact blocks 16a.

The tongues of the relays TR and TRl` are normally held against thevleft hand contacts under the pull-of the coils 23, 23 which areconstantl weaker than either el, the other coils. As soon, therefore, asthe brush BR1 leaves the last segment of ring S1 connected to contactblock 16, thereby breaking the circuit through coils 31, 31, the tongue`of rela TR will swing back against the left han contact so that thecable Will again be grounded through the tongues of the two relays.

When the brush BR2 passes over the segment for ring S2 connected tocontact energized but are' block 15", the minus and plus contacts 2 ofthe transmitter T will be connected with l positive currentj Will Howtherethrough if the minus contact or the plus contact of the transmitteris against the .corresponding block a. or b. lf, however, there Was noperforation of the tape 'corresponding with the position 2, no currentwill flow through -vthe relay coils and their tongues Will remainagainst the left hand contacts.

-The cable Will, therefore, remain grounded forv this second position,or as it is usually termed, zero current will be transmitted to thecable.

When the brush BR, passes over the seg,- ment of ring S2 connected tocontact block 15, the minus and plus contacts 3 of the transmitter willbe connected in circuit with the relay coils 20, 20. lf the plus contactis in contact With the transmitter bar at this instant, a positivecurrent impulse will flow through the lcoils 20, 20 and the tongue ofrelay TR Willmove over against the right hand contact, thereby causing apositive current impulse to be sen't through the cable from battery 30.As the brush BR, passes over the segments ot ring S, connected tocontact block 16 a circuit will be closed through the lockin coils 3l,31 to hold the tongue ci relay f R to Ward the right iur a period afterthe brush BR, left the segments of ring S2 connected with contact block15,Athereby prolonging the current impulse sent into the cable. Duringthis interval when the last impulse is l being sent into the cable, thebrush BRZ, contacts with' contact block 18 of the segment kring S3thereby energizing transmitter magnet 17, which actuates thetransmitter, causing the movable contacts toshitt against their backstops 14, and

simultaneously moving the tape forward to bring the next succeeding setof perforations into alignment with the transmitter selecting pins. 'Thelatter immediately enter the periorations of the tape thereby causingthecorresponding minus and plus contacts to move over into contact withthe transmitter bars a, b, in readiness to transmit current impulsestothe transmitting relays as the brushes of the` distributer again ln thediagram l have shown the rings1 divided into thirty segments, that is,ten for each of the three impulses of a code character, and six segmentsof each group are connected or strappedtogether by means of the contactblocks 16, 16b and l6,.respec time allotted to an impulse and if tenblocks are connected together, the impulses Will occupy 100% of the timeallotted toan impulse and there would then be no interval between theseparate impulses of a code character.' This adjustment of the number ofparts of each contact block forms a very convenient method of`determining the length of the impulses of the code charac-f ters.

Consider now the operation of the apparatus at, the receiving end of thecable. The cable relay CR swings against one contact 'orthe other inresponse to the positive and negative current impulses and remains inunoperated position when the current is Zero. Thel relays Ru, Rb, .arenormally biased against their left hand back stops in any suitablemanner, and are energized from the battery L.t0 in res onse to themovements of the relay QR. T ey are very sensitive and operate quicklyand with precision the instant a circuit is closed through battery 4:0by the cable relay; y

The control relays C and CL which transmit ,the positive and negativeimpulses respectively to the selecting relays through the distributer Dare' preferably provided with biasingI coils 42, 42 through which akWeak current constantly flows to normall bias the armature tonguesagainst the le hand back stops.

As previousy stated, the distributors at the sendin and receivinstations are o erated. in synchronism by synchronizing and phasecorrecting apparatus such as disclosed armature tongue to swing overagainst its i'ront contact as indicated in dotted lines. A current'`will flow from battery 41 throufrh the back stop and tongue of relay n,through. the coils 43, 43 of relays C and CL", and return to batterythrough the front i contact ,fand tongue of relay Rb. The coils ofrelays CL 'and CL) are reversely connected so that the current thusimpressed Will cause the tongue of relay CL (which Jresponds to minus ornegative impulses) to swing over against its front stop, as indicated'in dotted lines. A minus current will `thenl be sent from battery 50through the actuating coils of selecting relays 7, and 1, as the brushBiti passes over the segment of ring S4 connected at 15a' to theconductor connected to the coils of said selecting relays. inasmuch laolas the coils of the selecting relays 1', and r, are reversely connected,only the tongue of relay r1 which responds to minus impulses, will beoperated.

' The receiving segments l5, l5b and 15- of the segmented ring S, of thedistributer D are much narrower than the' corresponding segments ofrings S1 and S2 of the distributer" D at the sending station, since acurrent impulse of very short duration from the local battery orgenerator 50 is sucient to actuate tlie selecting relays. Furthermore,these receiving segments of ring S4 are so arranged with respect to thetransmitting segments of rings S1 and S2 that the impulses transmittedto the selecting relays occupy an intermediate part of the time intervalof the transmitted signal current. The marking impulse transmitted bythe distributer at the receiving station therefore occurs when thetransmitted current impulse circuit is closed at its front or Waveihasreached its most steady and accurate form, since the variations andinaccuracies occur mainly during the first and last parts of the currentwave.

In order that the armature tongues of the lselecting relays shall remainin their operated positions, after the brushes of the distributer D havemoved oit of the corresponding segments, so that the entire codecharacter may be set up en the selecting magnets and to provide for andyerlapnn order that the printer operation may take; place at the sametime that the impulses r the succeeding code character are beinglreceived, -the selecting relays are provide with locking coils in thecircuit leading to the translator magnetsA which is closed through theton es oi4 the relays and the front contacts. his holding or lockingcircuit is maintained throu hthe armature of the clear-out rela 45 untilthe latter is energized as the distri liter brush BR, passes over thesegment of rin S, comiected to contact block 19. As the oclring circuitis broken at the back stop of the clear out relay, a stop through theprinting pulse magnet 46. 1

The foregoing detailed description of the manner of operatingmy systemof ocean telegraphy adapted or use with three-unit code characters willmake clear to engineers the advantages which this system ossesses overprior methods of operating cab es. ot only is both the transmission andreceiving of messages made entirely automatic. but the time required forthe transmission `is materially shortened which is a very importantfactor in the commercial operation of cable telegranhy. Moreover, themarking intervals occupy only a portion of the. time interval of thetransmitted signal impulses, Ithus providing larger intervals forlcharacteristic irregularities in cable signalling and for the operationof the synchronizing and merece phase correcting devieesand therebycontributing'to greatera'ccuracyin the opera-- tion of the system.

I claim 'v1'. A synchronous telegraph system' wherein the code signalsare automatically transmitted and received, comprisinga tapecontrolledtransmitter, apair'oii transmitting relays operating respectively toconnect the line or cable with the positive or negativepole of anelectric source7 anda distributer having segments connected to contartsot' said transmitter and connected in sequence to the coils of saidrelays, said segments being less in number than said contacts.

2 A synchronous telegraph system as set forth in claim 1, each of saiddistributer segments being connected to a plurality of said transmittercontacts.

A synchronous telegraph system wherein the code signals areautomatically transmitted and received, comprising an automatictape-controlled transmitter:transmitting relays operating respectivelyto connect the line or cable with the positive or negative pole of anelectric source, a distributer provided with segmented members havingelements connected to said transmitter and successively connected incircuit with the coils of all of said relays` and means for maintainingsaid relays in operated position for a predetermined period after thetransmitter has been disconnected therefrom.

4. A synchronous telegraph system Whereinthe code signals areautomatically transmitted and received, comprising Ian Iaiitomatictape-controlled transmitter, transmitting relays operating respectivelyto connect the linepor cable with the positive or negative pole'of anelectric source', a distributer provided with segmentscpnnected to saidtransmitter and successive] connected in circuit with the coils of saidYrelays, vand an additional segmented member on. said distributer havingsegments connected to hold-` the current impulse transmittedito thecable.

5; A'n automatic telegraphl system, comprising synchronously operatedcurrent distributers at the transmitting and receiving stations, a pairof relays interposed between the distributers and the cable., atape-controlled transmitter having conn'ected pairs of contacts, themembers of each pair cooperating respectively with contacts connected toopposite oles of an electric source, and a pair of se ectiii relaysarranged in reversely connected pa positive or negative impulses /to thetranslator magnets of a, printer, theT distribiiters through the holdingcoil of the actuated relay to prolong ice llO

rs and adapted'to transmit A 1,43 pees having active segments equalonly-to the number of pairs of transmitter contacts.

6. A synchronous telegraph system Wherein the code signals areautomatically transmitted and'received. comprising an automatictape-controlled transmitter, a pair of transmitting` relays respectivelyoperating to connect the line or cable with the positive or negativepole of an electric generator, a distributer provided with segmentedmem'- bers having elements connected to said transmitter andsuccessively connected in circuit with the coils of said maintainingsaid relays in qperated positio for a predetermined period after thetransmitter has been disconnected therefrom` receiving apparatuscomprising' a cable relay and auxiliary relays operating respectively totransmit positive and negativeimpulses, a pair of selecting relaysarranged in reversely connected pairs, operating to transmitrespectively positive or negative impulses to thc translator magnetsoi'aprinter, and a distributer operating synchronously with theirst-named distributer to connect said auxiliary relays to saidselecting relays for shorter time intervals than said transmittingrelays are connected to the cable.

7. A telegraph system wherein the cable signals are automaticallytransmitted an'd received, comprising synchronously operated currentdistributers at the transmitting and receiving.,r stations, a .pair ofrelays interposed between the distributers and the cable, and means forprolonging the current impulses transmitted to the cable a predetermined interval after the termination oi the operating impulse fromthe distributor to the relay. I

8. A telegraph system wherein the cable signals are automatically'transmitted relays, means for the distributer at the receiving stationto oocupy only an intermediate portion o1P the intlval of thecorresponding transmitted signal.

9. A synchronous telegraph system wherein theasignals are automaticallytransmitted and recorded and the code charactersl are composed ofcombinations of positive, negative and zero current impulses, comprising-an automatic tape-controlled transmitter having' sets of stationarycontacts directly connected respectively to the positive and negativepoles of a generator, a plurality of pairs of connected contacts movableindividually into contact with said stationary contacts under thecontrol of the perforated characters in the tape, a distributer havingsegmented members separated elements of which are connected in sequenceto said pairs of movable contacts, a pair of relays correspondingrespectively to positive and negative current impulses, and operating toconnect the cable with corresponding poles of a. generator, and brushesmovable over the members of said distributer and operating` to connectthe actuating coils of the relays successively with said separatedelements.

In testimony whereof, I aix my signature.

HERBERTV wenn

